Culver Academies’ chemistry students were given a hypothetical question which may face us all in the near future: What alternative fuel would you choose to reduce carbon emissions?
The students were presented with this scenario: A federal law is passed requiring gas stations to carry two types of fuel by 2050. The options are fossil fuels, biodiesel, compressed hydrogen, and ethanol, with goal being to reduce carbon dioxide emissions.
Since the vast majority of service stations already carry gasoline, a fossil fuel, each group looked at which fuel would make the best second option. It then made a presentations defending the selection before a mock congressional committee comprised of volunteer instructors.
In Andrew Basner’s first class on Dec. 7, committee members decided to back the plan proposed by the group of Sophie George ’19 (Indianapolis), Brooke Ditmire ’18 (Culver), Nicolas Ortega ’18 (Jamundi, Colombia), and Jackson Reid ’17 (Guelph, Ontario).
The program they developed consisted of dividing the country into regions and the alternative fuel would be chosen based on the requirements needed. Where carbon dioxide reduction is a major priority, such as California and the surrounding states, the best fit would be hydrogen fuel cells because those cars release zero emissions.
Biodiesel would be a good fit in the southern states because of the warmer temperatures. While biodiesel reduces carbon dioxide emissions, the fuel also has the reputation of jelling in cold weather. Ethanol would be used where corn, which is the primary crop used to make the fuel, is plentiful.
Each group had to weigh the pros and cons of each fuel. Gasoline (fossil fuels) is the most efficient energy producer but it also the most polluting. Hydrogen fuel cells are the cleanest but produce the least amount of energy. They are also expensive to produce and special refueling stations would have to be built.
Biodiesel can be made from a variety of sources, including old cooking oil, but it produces less energy than gasoline and is more expensive, too. The cold weather can also be a drawback, students said.
Ethanol is less energy efficient than gasoline, which causes a reduction in miles per gallon. One of the biggest controversies surrounding the fuel is the diversion of a feed crop for energy production. There is also the question of how high the blended fuel can go. E-85 sold now is 85 percent ethanol. All gasoline contains 10 percent ethanol. Students noted that only certain cars are able to run the E-85 fuel without damaging the engines.
The three alternative fuel types are considered renewable, while gasoline is not. However, gasoline’s higher octane levels deliver more power per unit, the different groups pointed out.